(Google punishes viewers who make themselves less valuable to advertisers by giving them an entirely blank homepage.)
One wonders if you couldn't whip up something that would whip up a list of choices by operating locally only on the users history returning just a list of things to show on the page and forgetting it when the user closed the tab.
As for what they should do, I think populating the homepage from the subscriptions list (either literally as an ordered list or by some algorithmic "watch time vs average watch time for this creator", I don't care) would be preferable.
If the goal were anything but discouraging disabling watch history, they’d take care to design a page not so strikingly barren.
Video categories, subscriptions, trending searches (not saying we’d WANT that), Google-curated selections, recommendations based on user choices (“what kinds of videos should we show you, want daily news/sportballs/music recs?”)